Today's digital cameras take essentially a 2D image of the 3D world. What if for each pixel, they also recorded the distance. Perhaps with a future version of PhotoShop, you might be able to change the camera's position within the photo. Such images would also be useful for creating ultra realistic
quake-like adventure games. The ability to stitch multiple such 3D images together would also be very interesting indeed.

I once saw a somewhat-oversized disposable camera with three lens/shutter assemblies on the front. After taking (IIRC) twelve pictures, you would send the camera to the manufacturer, who would send you back 3-D pictures with a built-in lenticular filter (similar to the 3D fronts on videocasette boxes etc.) Cool concept, but I don't think it ever caught on and I haven't seen one in ages.

BTW, the lenses were spaced rather widely, I think four film-frames apart, and each use of the winder would advance the film three frames. Thus, after having shot five pictures, assuming three views of the first picture are A, a, and 1; the second picture B, b, and 2, etc. the film would hold

Haven't seen that particular one...Used to be a camera with four lenses in a slightly curved set, whose name I can't rememeber that did something similar. You take a picture, it took four seperate pictures using two frames of film <each lens used half a frame> and when the roll was done, you send it to the manufacturer for an expensive processing job, and got back a 'flicker' picture. The kind of thing that goes 'zweep!' when you scratch your fingernail across it and makes cats attack you. Turning it slightly gives you a bit of a 3-d effect, you can look outside the border of the picture.

Realviz Imagemodeler, Eon Photomodeler Pro, a few others working on it. Eyetronics just announced a camera that sort of does this, with many limitations. Software approaches need lots of user intervention. Original SynaPix goal was full automation from any series of images at all; they learned enough to know that it's actually a really thorny set of challenges.

I'm working on a project that uses a pair of 35mm cameras mounted closely together achieve a stereo image. The same could be done with a pair of digital cameras. The image could be viewed as a pair of prints mounted in a "stereograph," or through LCD displays held in front of the viewers face- much like an "electronic stereograph."